This invention relates to an electric distribution block which is mounted in an engine room of a vehicle or the like so as to supply a source current from a battery to various electrical equipments, and the invention also relates to a method of assembling bus bars on an electric distribution block.
An electric distribution block is a relay-purpose electric distribution part for supplying a source current from a battery to meters, switches, lamps and other electrical equipments, and this electric distribution block is mounted, for example, in an engine room of an automobile or around an instrument panel. The electric distribution block is a constituent assembling part of an electric distribution box, and in some cases, the electric distribution block cooperates with other electric distribution block to form a relay circuit or a fuse circuit or to form an ECU (Electronic Control Unit) for controlling various electrical equipments.
An electric distribution box has a box-like shape, and is called a relay box, a fuse box, a junction box or others. The electric distribution box includes an electric distribution block, a lower cover, an upper cover closing an opening in the lower cover. The electric distribution block is called a relay block, a fuse block, a junction block or others.
The electric distribution block is fixedly secured to the lower cover by retaining member, and is detachably fixed thereto so that it will not shake during the travel of the vehicle so as not to produce abnormal sounds, and will not be disengaged from the lower cover.
FIG. 5 shows one related electric distribution block of the type described which has been proposed by the Applicant of the present application (See, JP-A-2000-83313 (Pages 3 and 4, FIG. 1)). As shown in this Figure, the electric distribution block 100 includes a wiring board assembly 101 (serving as a block body) consisting of three stacked wiring boards 102, 102 and 102, a connector cavity member 104 releasably fixed to the wiring board assembly 101, bus bars 108 mounted on and over upper and lower surfaces of the wiring boards 102, and terminal portions 112 which are electrically connected at their one ends to the bus bars 108, and have the other end portions for insertion into the connector cavity member 104. The electric distribution block 100 is fixedly held between a (lower-side) lower cover 116 and an (upper-side) upper cover 117, and therefore is protected from external interference or others.
The wiring board 102 is molded of an insulative synthetic resin. A receiving hole 103 for receiving the lower end portions of the terminal portions 112 and terminal holding portions 106 of the connector cavity member 104 is formed through the upper wiring board 102.
The connector cavity member 104, serving as a connector mounting portion, includes a cavity body 105 for receiving a wire-side connector (not shown) connected to external circuits, and the terminal holding portion 106 formed on and projecting downwardly from an inner wall of the cavity body 105.
The bus bar 108 is formed by blanking a piece from an electrically-conductive metal sheet and then by bending this piece, and the bus bar has a flat portion 109 and a bent portion 110. The bent portion 110 is bent at right angles or at generally right angles, and is held in intimate contact with an inner peripheral surface of the receiving hole 103.
Like the bus bar 108, the terminal portion 112 is formed by blanking a piece from an electrically-conductive metal sheet and then by bending this piece. The terminal portion 112 includes a body portion 113, and a lower end portion of this body portion 113 is curved to form an integral resilient contact portion 114.
However, the above related electric distribution block 100 has the following problems to be solved.
Firstly, in the electric distribution block 100, the bus bars 108 and the terminal portions 112 are formed separately from each other, and also the wiring board assembly 101 and the connector cavity member 104 are formed separately from each other. Therefore, there is encountered a problem that the number of the component parts increases, so that the cost increases.
Secondly, the bus bars 108 and the terminal portions 112 which form internal circuits are mounted on the wiring board assembly 101, and the connector cavity member 104 is mounted in the receiving hole 103 in the wiring board assembly 101. By doing so, the electric distribution block 100 is assembled. Therefore, there is encountered a problem that the number of the component parts is large, so that much time is required for assembling the electric distribution block 100.
And besides, the connector cavity member 104 must be attached to the upwardly-projecting terminal portions 112 from the upper side, and there is a fear that the distal ends of the terminal portions 112 strike against the inner wall of the connector cavity member 104, and are bent.